Switching networks are useful as fast circuits for routing data. Switching networks consist of input terminals, a plurality of switching circuits, interconnections or links, and output terminals. A switching circuit is operable to route two signals appearing at its inputs to either of two outputs. The route through the switching circuit is dictated by an external controller. Switching networks are useable, for example, in telephone switchboards, the switching fabric of Asynchronous Transfer Mode (ATM) switches and the like.
It is desirable to implement switching networks into an ever-decreasing area within an electrical circuit. A given network has, however, a characteristic number of switching circuits as a function of the number of network inputs. But, there are at least two degrees of freedom available for use in developing a network layout. A first is the layout of network switching circuits, i.e., their placement on a grid relative to one another. A second is the layout of the interconnects linking such switching circuits. In fact, those two aspects of a network layout may be of paramount importance in determining network area requirements.